Conventional linear frequency modulated continuous wave (LFMCW) radars include wideband-type radars and gated-type radars. A wideband LFMCW radar often covers a large distance range and has a wideband receiver. The wideband receiver often has a high noise floor. As a result, a wideband LFMCW radar often requires a high-power transmitter. A gated LFMCW radar often has a narrowband receiver, but it only covers a small distance range at any instance. The abovementioned issues limit the application of LFMCW radars.